<script>
import { isActive, hashRE, groupHeaders } from "../utils";

export default {
  functional: true,
  props: ["item"],
  render(h, { parent: { $page, $site, $route }, props: { item } }) {
    // use custom active class matching logic
    // due to edge case of paths ending with / + hash
    const selfActive = isActive($route, item.path);
    // for sidebar: auto pages, a hash link should be active if one of its child
    // matches
    const active =
      item.type === "auto"
        ? selfActive ||
          item.children.some(c =>
            isActive($route, item.basePath + "#" + c.slug)
          )
        : selfActive;
    const link = renderLink(h, item.path, item.title || item.path, active);
    const configDepth =
      $page.frontmatter.sidebarDepth != null
        ? $page.frontmatter.sidebarDepth
        : $site.themeConfig.sidebarDepth;
    const maxDepth = configDepth == null ? 1 : configDepth;
    if (item.type === "auto") {
      return [
        link,
        renderChildren(h, item.children, item.basePath, $route, maxDepth)
      ];
    } else if (active && item.headers && !hashRE.test(item.path)) {
      const children = groupHeaders(item.headers);
      return [link, renderChildren(h, children, item.path, $route, maxDepth)];
    } else {
      return link;
    }
  }
};

function renderLink(h, to, text, active) {
  return h(
    "router-link",
    {
      props: {
        to,
        activeClass: "",
        exactActiveClass: ""
      },
      class: {
        active,
        "sidebar-link": true
      }
    },
    text
  );
}

function renderChildren(h, children, path, route, maxDepth, depth = 1) {
  if (!children || depth > maxDepth) return null;
  return h(
    "ul",
    { class: "sidebar-sub-headers" },
    children.map(c => {
      const active = isActive(route, path + "#" + c.slug);
      return h("li", { class: "sidebar-sub-header" }, [
        renderLink(h, "#" + c.slug, c.title, active),
        renderChildren(h, c.children, path, route, maxDepth, depth + 1)
      ]);
    })
  );
}
</script>

<style lang="stylus">
@import '../styles/config.styl';

.sidebar .sidebar-sub-headers {
  padding-left: 1rem;
  font-size: 0.95em;
}

a.sidebar-link {
  font-weight: 400;
  display: inline-block;
  color: $textColor;
  border-left: 0.25rem solid transparent;
  padding: 0.35rem 1rem 0.35rem 1.25rem;
  line-height: 1.4;
  width: 100%;
  box-sizing: border-box;

  &:hover {
    color: $accentColor;
  }

  &.active {
    font-weight: 600;
    color: $accentColor;
    border-left-color: $accentColor;
  }

  .sidebar-group & {
    padding-left: 2rem;
  }

  .sidebar-sub-headers & {
    padding-top: 0.25rem;
    padding-bottom: 0.25rem;
    border-left: none;

    &.active {
      font-weight: 500;
    }
  }
}
</style>
